[S390] Add PSW restart shutdown trigger
Michael Holzheu [Wed, 3 Aug 2011 14:44:19 +0000 (16:44 +0200)]
With this patch a new S390 shutdown trigger "restart" is added. If under
z/VM "systerm restart" is entered or under the HMC the "PSW restart" button
is pressed, the PSW located at 0 (31 bit) or 0x1a0 (64 bit) bit is loaded.
Now we execute do_restart() that processes the restart action that is
defined under /sys/firmware/shutdown_actions/on_restart. Currently the
following actions are possible: reipl (default), stop, vmcmd, dump, and
dump_reipl.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

arch/s390/include/asm/lowcore.h
arch/s390/include/asm/system.h
arch/s390/kernel/asm-offsets.c
arch/s390/kernel/entry.S
arch/s390/kernel/entry64.S
arch/s390/kernel/ipl.c
arch/s390/kernel/setup.c
arch/s390/kernel/smp.c
arch/s390/mm/maccess.c

index f26280d..e85c911 100644 (file)
@@ -18,6 +18,7 @@ void system_call(void);
 void pgm_check_handler(void);
 void mcck_int_handler(void);
 void io_int_handler(void);
+void psw_restart_int_handler(void);
 
 #ifdef CONFIG_32BIT
 
@@ -150,7 +151,10 @@ struct _lowcore {
         */
        __u32   ipib;                           /* 0x0e00 */
        __u32   ipib_checksum;                  /* 0x0e04 */
-       __u8    pad_0x0e08[0x0f00-0x0e08];      /* 0x0e08 */
+
+       /* 64 bit save area */
+       __u64   save_area_64;                   /* 0x0e08 */
+       __u8    pad_0x0e10[0x0f00-0x0e10];      /* 0x0e10 */
 
        /* Extended facility list */
        __u64   stfle_fac_list[32];             /* 0x0f00 */
@@ -286,7 +290,10 @@ struct _lowcore {
         */
        __u64   ipib;                           /* 0x0e00 */
        __u32   ipib_checksum;                  /* 0x0e08 */
-       __u8    pad_0x0e0c[0x0f00-0x0e0c];      /* 0x0e0c */
+
+       /* 64 bit save area */
+       __u64   save_area_64;                   /* 0x0e0c */
+       __u8    pad_0x0e14[0x0f00-0x0e14];      /* 0x0e14 */
 
        /* Extended facility list */
        __u64   stfle_fac_list[32];             /* 0x0f00 */
index d382629..6582f69 100644 (file)
@@ -113,6 +113,7 @@ extern void pfault_fini(void);
 
 extern void cmma_init(void);
 extern int memcpy_real(void *, void *, size_t);
+extern void copy_to_absolute_zero(void *dest, void *src, size_t count);
 
 #define finish_arch_switch(prev) do {                                       \
        set_fs(current->thread.mm_segment);                                  \
index 05d8f38..199a537 100644 (file)
@@ -142,6 +142,7 @@ int main(void)
        DEFINE(__LC_FPREGS_SAVE_AREA, offsetof(struct _lowcore, floating_pt_save_area));
        DEFINE(__LC_GPREGS_SAVE_AREA, offsetof(struct _lowcore, gpregs_save_area));
        DEFINE(__LC_CREGS_SAVE_AREA, offsetof(struct _lowcore, cregs_save_area));
+       DEFINE(__LC_SAVE_AREA_64, offsetof(struct _lowcore, save_area_64));
 #ifdef CONFIG_32BIT
        DEFINE(SAVE_AREA_BASE, offsetof(struct _lowcore, extended_save_area_addr));
 #else /* CONFIG_32BIT */
index 3eab7cf..02ec8fe 100644 (file)
@@ -849,6 +849,34 @@ restart_crash:
 restart_go:
 #endif
 
+#
+# PSW restart interrupt handler
+#
+ENTRY(psw_restart_int_handler)
+       st      %r15,__LC_SAVE_AREA_64(%r0)     # save r15
+       basr    %r15,0
+0:     l       %r15,.Lrestart_stack-0b(%r15)   # load restart stack
+       l       %r15,0(%r15)
+       ahi     %r15,-SP_SIZE                   # make room for pt_regs
+       stm     %r0,%r14,SP_R0(%r15)            # store gprs %r0-%r14 to stack
+       mvc     SP_R15(4,%r15),__LC_SAVE_AREA_64(%r0)# store saved %r15 to stack
+       mvc     SP_PSW(8,%r15),__LC_RST_OLD_PSW(%r0) # store restart old psw
+       xc      __SF_BACKCHAIN(4,%r15),__SF_BACKCHAIN(%r15) # set backchain to 0
+       basr    %r14,0
+1:     l       %r14,.Ldo_restart-1b(%r14)
+       basr    %r14,%r14
+
+       basr    %r14,0                          # load disabled wait PSW if
+2:     lpsw    restart_psw_crash-2b(%r14)      # do_restart returns
+       .align 4
+.Ldo_restart:
+       .long   do_restart
+.Lrestart_stack:
+       .long   restart_stack
+       .align 8
+restart_psw_crash:
+       .long   0x000a0000,0x00000000 + restart_psw_crash
+
        .section .kprobes.text, "ax"
 
 #ifdef CONFIG_CHECK_STACK
index 7a0fd42..5f729d6 100644 (file)
@@ -865,6 +865,26 @@ restart_crash:
 restart_go:
 #endif
 
+#
+# PSW restart interrupt handler
+#
+ENTRY(psw_restart_int_handler)
+       stg     %r15,__LC_SAVE_AREA_64(%r0)     # save r15
+       larl    %r15,restart_stack              # load restart stack
+       lg      %r15,0(%r15)
+       aghi    %r15,-SP_SIZE                   # make room for pt_regs
+       stmg    %r0,%r14,SP_R0(%r15)            # store gprs %r0-%r14 to stack
+       mvc     SP_R15(8,%r15),__LC_SAVE_AREA_64(%r0)# store saved %r15 to stack
+       mvc     SP_PSW(16,%r15),__LC_RST_OLD_PSW(%r0)# store restart old psw
+       xc      __SF_BACKCHAIN(8,%r15),__SF_BACKCHAIN(%r15) # set backchain to 0
+       brasl   %r14,do_restart
+
+       larl    %r14,restart_psw_crash          # load disabled wait PSW if
+       lpswe   0(%r14)                         # do_restart returns
+       .align 8
+restart_psw_crash:
+       .quad   0x0002000080000000,0x0000000000000000 + restart_psw_crash
+
        .section .kprobes.text, "ax"
 
 #ifdef CONFIG_CHECK_STACK
index a689070..059c590 100644 (file)
  * - halt
  * - power off
  * - reipl
+ * - restart
  */
 #define ON_PANIC_STR           "on_panic"
 #define ON_HALT_STR            "on_halt"
 #define ON_POFF_STR            "on_poff"
 #define ON_REIPL_STR           "on_reboot"
+#define ON_RESTART_STR         "on_restart"
 
 struct shutdown_action;
 struct shutdown_trigger {
@@ -1544,17 +1546,20 @@ static char vmcmd_on_reboot[128];
 static char vmcmd_on_panic[128];
 static char vmcmd_on_halt[128];
 static char vmcmd_on_poff[128];
+static char vmcmd_on_restart[128];
 
 DEFINE_IPL_ATTR_STR_RW(vmcmd, on_reboot, "%s\n", "%s\n", vmcmd_on_reboot);
 DEFINE_IPL_ATTR_STR_RW(vmcmd, on_panic, "%s\n", "%s\n", vmcmd_on_panic);
 DEFINE_IPL_ATTR_STR_RW(vmcmd, on_halt, "%s\n", "%s\n", vmcmd_on_halt);
 DEFINE_IPL_ATTR_STR_RW(vmcmd, on_poff, "%s\n", "%s\n", vmcmd_on_poff);
+DEFINE_IPL_ATTR_STR_RW(vmcmd, on_restart, "%s\n", "%s\n", vmcmd_on_restart);
 
 static struct attribute *vmcmd_attrs[] = {
        &sys_vmcmd_on_reboot_attr.attr,
        &sys_vmcmd_on_panic_attr.attr,
        &sys_vmcmd_on_halt_attr.attr,
        &sys_vmcmd_on_poff_attr.attr,
+       &sys_vmcmd_on_restart_attr.attr,
        NULL,
 };
 
@@ -1576,6 +1581,8 @@ static void vmcmd_run(struct shutdown_trigger *trigger)
                cmd = vmcmd_on_halt;
        else if (strcmp(trigger->name, ON_POFF_STR) == 0)
                cmd = vmcmd_on_poff;
+       else if (strcmp(trigger->name, ON_RESTART_STR) == 0)
+               cmd = vmcmd_on_restart;
        else
                return;
 
@@ -1707,6 +1714,34 @@ static void do_panic(void)
        stop_run(&on_panic_trigger);
 }
 
+/* on restart */
+
+static struct shutdown_trigger on_restart_trigger = {ON_RESTART_STR,
+       &reipl_action};
+
+static ssize_t on_restart_show(struct kobject *kobj,
+                              struct kobj_attribute *attr, char *page)
+{
+       return sprintf(page, "%s\n", on_restart_trigger.action->name);
+}
+
+static ssize_t on_restart_store(struct kobject *kobj,
+                               struct kobj_attribute *attr,
+                               const char *buf, size_t len)
+{
+       return set_trigger(buf, &on_restart_trigger, len);
+}
+
+static struct kobj_attribute on_restart_attr =
+       __ATTR(on_restart, 0644, on_restart_show, on_restart_store);
+
+void do_restart(void)
+{
+       smp_send_stop();
+       on_restart_trigger.action->fn(&on_restart_trigger);
+       stop_run(&on_restart_trigger);
+}
+
 /* on halt */
 
 static struct shutdown_trigger on_halt_trigger = {ON_HALT_STR, &stop_action};
@@ -1783,7 +1818,9 @@ static void __init shutdown_triggers_init(void)
        if (sysfs_create_file(&shutdown_actions_kset->kobj,
                              &on_poff_attr.attr))
                goto fail;
-
+       if (sysfs_create_file(&shutdown_actions_kset->kobj,
+                             &on_restart_attr.attr))
+               goto fail;
        return;
 fail:
        panic("shutdown_triggers_init failed\n");
index 0c35dee..18640ff 100644 (file)
@@ -346,7 +346,7 @@ setup_lowcore(void)
        lc = __alloc_bootmem_low(LC_PAGES * PAGE_SIZE, LC_PAGES * PAGE_SIZE, 0);
        lc->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
        lc->restart_psw.addr =
-               PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
+               PSW_ADDR_AMODE | (unsigned long) psw_restart_int_handler;
        if (user_mode != HOME_SPACE_MODE)
                lc->restart_psw.mask |= PSW_ASC_HOME;
        lc->external_new_psw.mask = psw_kernel_bits;
@@ -529,6 +529,27 @@ static void __init setup_memory_end(void)
                memory_end = memory_size;
 }
 
+void *restart_stack __attribute__((__section__(".data")));
+
+/*
+ * Setup new PSW and allocate stack for PSW restart interrupt
+ */
+static void __init setup_restart_psw(void)
+{
+       psw_t psw;
+
+       restart_stack = __alloc_bootmem(ASYNC_SIZE, ASYNC_SIZE, 0);
+       restart_stack += ASYNC_SIZE;
+
+       /*
+        * Setup restart PSW for absolute zero lowcore. This is necesary
+        * if PSW restart is done on an offline CPU that has lowcore zero
+        */
+       psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
+       psw.addr = PSW_ADDR_AMODE | (unsigned long) psw_restart_int_handler;
+       copy_to_absolute_zero(&S390_lowcore.restart_psw, &psw, sizeof(psw));
+}
+
 static void __init
 setup_memory(void)
 {
@@ -792,6 +813,7 @@ setup_arch(char **cmdline_p)
        setup_addressing_mode();
        setup_memory();
        setup_resources();
+       setup_restart_psw();
        setup_lowcore();
 
         cpu_init();
index a6d85c0..70f4b96 100644 (file)
@@ -468,6 +468,11 @@ int __cpuinit start_secondary(void *cpuvoid)
        ipi_call_lock();
        set_cpu_online(smp_processor_id(), true);
        ipi_call_unlock();
+       __ctl_clear_bit(0, 28); /* Disable lowcore protection */
+       S390_lowcore.restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
+       S390_lowcore.restart_psw.addr =
+               PSW_ADDR_AMODE | (unsigned long) psw_restart_int_handler;
+       __ctl_set_bit(0, 28); /* Enable lowcore protection */
        /* Switch on interrupts */
        local_irq_enable();
        /* cpu_idle will call schedule for us */
@@ -507,7 +512,11 @@ static int __cpuinit smp_alloc_lowcore(int cpu)
        memset((char *)lowcore + 512, 0, sizeof(*lowcore) - 512);
        lowcore->async_stack = async_stack + ASYNC_SIZE;
        lowcore->panic_stack = panic_stack + PAGE_SIZE;
-
+       lowcore->restart_psw.mask = PSW_BASE_BITS | PSW_DEFAULT_KEY;
+       lowcore->restart_psw.addr =
+               PSW_ADDR_AMODE | (unsigned long) restart_int_handler;
+       if (user_mode != HOME_SPACE_MODE)
+               lowcore->restart_psw.mask |= PSW_ASC_HOME;
 #ifndef CONFIG_64BIT
        if (MACHINE_HAS_IEEE) {
                unsigned long save_area;
index 51e5cd9..5dbbaa6 100644 (file)
@@ -85,3 +85,19 @@ int memcpy_real(void *dest, void *src, size_t count)
        arch_local_irq_restore(flags);
        return rc;
 }
+
+/*
+ * Copy memory to absolute zero
+ */
+void copy_to_absolute_zero(void *dest, void *src, size_t count)
+{
+       unsigned long cr0;
+
+       BUG_ON((unsigned long) dest + count >= sizeof(struct _lowcore));
+       preempt_disable();
+       __ctl_store(cr0, 0, 0);
+       __ctl_clear_bit(0, 28); /* disable lowcore protection */
+       memcpy_real(dest + store_prefix(), src, count);
+       __ctl_load(cr0, 0, 0);
+       preempt_enable();
+}